Shimon Edelstein1, Miriam Sudri2, Shibli Tanous2, Hila Ben Amram3, Adi Sharabi-Nov4, Inna Rozenfeld5, Hedva Halal5, Salman Zarka6. 1. Infectious Diseases Unit, Ziv Medical Center and Tel-Hai Academic Collage, Tel-Hai, Israel. shimone@ziv.gov.il. 2. Infectious Diseases Unit, Ziv Medical Center and Tel-Hai Academic Collage, Tel-Hai, Israel. 3. Clinical Microbiology Laboratory, Ziv Medical Center and Tel-Hai Academic Collage, Tel-Hai, Israel. 4. Statistical Unit, Ziv Medical Center and Tel-Hai Academic Collage, Tel-Hai, Israel. 5. Emergency Department, Ziv Medical Center, Safed, Israel. 6. Management, Ziv Medical Center, Safed, Israel.
Abstract
PURPOSE: Since 2020, a SARS-COV2 epidemic has been raging worldwide. The cycle of the PCR test in which the virus is detected is called cycle threshold (CT). The method of obtaining the sample is not detailed in any published study and is based on general guidelines of the CDC. Our contention is that the manner in which the sample is obtained has a dramatic effect on CT values. METHODS: For each person suspected of having Covid-19 who arrives at the emergency room, two swabs are taken in succession, one according to CDC guidelines and the other according to "Ziv" guidelines. The Ziv method sample collection guidelines determine the depth of penetration, the number of rotations of the swab, and their direction. Each double sample was sent for analysis. RESULTS: Analysis of the CT results of the sample to results methods and of the Seegene platform clearly found (p = 0.003 and p = 0.001, respectively) that more rigorous sample collection yielded lower CT values. CONCLUSION: The method of obtaining the samples had a dramatic effect on CT results. Any publication that includes CT results, and certainly studies that discuss CT kinetics, must describe in detail the method by which the samples were obtained. In places where it is also important to detect the onset of illness (airports, hospitals, schools, etc.), it is important to use the Ziv method to reduce the risk of false negatives.
PURPOSE: Since 2020, a SARS-COV2 epidemic has been raging worldwide. The cycle of the PCR test in which the virus is detected is called cycle threshold (CT). The method of obtaining the sample is not detailed in any published study and is based on general guidelines of the CDC. Our contention is that the manner in which the sample is obtained has a dramatic effect on CT values. METHODS: For each person suspected of having Covid-19 who arrives at the emergency room, two swabs are taken in succession, one according to CDC guidelines and the other according to "Ziv" guidelines. The Ziv method sample collection guidelines determine the depth of penetration, the number of rotations of the swab, and their direction. Each double sample was sent for analysis. RESULTS: Analysis of the CT results of the sample to results methods and of the Seegene platform clearly found (p = 0.003 and p = 0.001, respectively) that more rigorous sample collection yielded lower CT values. CONCLUSION: The method of obtaining the samples had a dramatic effect on CT results. Any publication that includes CT results, and certainly studies that discuss CT kinetics, must describe in detail the method by which the samples were obtained. In places where it is also important to detect the onset of illness (airports, hospitals, schools, etc.), it is important to use the Ziv method to reduce the risk of false negatives.
Authors: Sandra Domeracki; Robert N Clapp; Kristopher Taylor; Chuanyi M Lu; Harry Lampiris; Paul D Blanc Journal: J Occup Environ Med Date: 2020-11 Impact factor: 2.162
Authors: Jared Bullard; Kerry Dust; Duane Funk; James E Strong; David Alexander; Lauren Garnett; Carl Boodman; Alexander Bello; Adam Hedley; Zachary Schiffman; Kaylie Doan; Nathalie Bastien; Yan Li; Paul G Van Caeseele; Guillaume Poliquin Journal: Clin Infect Dis Date: 2020-12-17 Impact factor: 9.079
Authors: Bernard La Scola; Marion Le Bideau; Julien Andreani; Van Thuan Hoang; Clio Grimaldier; Philippe Colson; Philippe Gautret; Didier Raoult Journal: Eur J Clin Microbiol Infect Dis Date: 2020-04-27 Impact factor: 3.267
Authors: Carlos Chaccour; Paula Ruiz-Castillo; Mary-Ann Richardson; Gemma Moncunill; Aina Casellas; Francisco Carmona-Torre; Miriam Giráldez; Juana Schwartz Mota; José Ramón Yuste; José Ramón Azanza; Miriam Fernández; Gabriel Reina; Carlota Dobaño; Joe Brew; Belen Sadaba; Felix Hammann; Regina Rabinovich Journal: Trials Date: 2020-06-08 Impact factor: 2.279